Yes, your base class has a non-trivial constructor (a constructor that takes more one argument or more), so the compiler cannot know which constructor to call or which arguments to pass in.
Here's where you come in. You need to tell the compiler by adding ": ConstructorName(args)" after the constructors in your derived class. Basically it tells the compiler which constructor in the base class to call and what arugments to pass.

Originally Posted by Adak

io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.

Originally Posted by Salem

You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

well, default constructors are constructors that YOU do not write, i.e. the compiler writes them for you.

This is not true. Default constructors are constructors that can be invoked with no arguments. What you are referring to are implicitly declared default constructors.

Originally Posted by Elysia

Yes, your base class has a non-trivial constructor (a constructor that takes more one argument or more), so the compiler cannot know which constructor to call or which arguments to pass in.

To elaborate: by default, a constructor for a class will invoke the default constructors of the non-static member variables and base classes. However, the Time class has a non-default constructor, thus it does not have an implicitly declared default constructor. As such, you either have to declare the default constructor, or since you were told not to do so, you have to use the constructor initialisation list as Elysia described.

Originally Posted by Bjarne Stroustrup (2000-10-14)

I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.